C fputs() and fgets()

The fputs() and fgets() functions are commonly used in the C programming language for reading and writing strings to files. They are part of the standard I/O library and provide a convenient way to handle file input and output.

Here’s a brief explanation of each function:

fputs(): The fputs() function is used to write a string to a file. Its syntax is as follows:

int fputs(const char *str, FILE *stream);

The str parameter is the string to be written to the file, and stream is a pointer to the FILE object representing the file. It returns a non-negative value on success and EOF (end-of-file) on failure.

Example usage:

FILE *file = fopen("file.txt", "w");
if (file != NULL) {
    if (fputs("Hello, World!", file) != EOF) {
        // Write successful
    }
    fclose(file);
}

2. fgets(): The fgets() function is used to read a string from a file. Its syntax is as follows:

char *fgets(char *str, int size, FILE *stream);

The str parameter is a character array where the read string will be stored, size is the maximum number of characters to be read, and stream is a pointer to the FILE object representing the file. It returns str on success and NULL on failure or when the end of the file is reached.

Example usage:

FILE *file = fopen("file.txt", "r");
if (file != NULL) {
    char buffer[100];
    if (fgets(buffer, sizeof(buffer), file) != NULL) {
        // Read successful
    }
    fclose(file);
}

Note that both functions require the file to be opened using fopen() in the appropriate mode ("w" for writing or "r" for reading) prior to calling them. Additionally, proper error handling should be implemented to check for potential failures in file opening or I/O operations.

Writing File : fputs() function

Certainly! Here’s an example of using the fputs() function to write a string to a file in C:

#include <stdio.h>

int main() {
    FILE *file = fopen("file.txt", "w");
    if (file != NULL) {
        char str[] = "Hello, World!";
        if (fputs(str, file) != EOF) {
            printf("String written to the file successfully.\n");
        } else {
            printf("Error writing to the file.\n");
        }
        fclose(file);
    } else {
        printf("Error opening the file.\n");
    }

    return 0;
}

In this example:

We include the <stdio.h> header file, which contains the necessary definitions for file operations.
We open the file “file.txt” in write mode using fopen(). If the file is opened successfully, a FILE pointer (file) is returned. Otherwise, we display an error message.
We define a string str that we want to write to the file.
We call fputs() to write the string to the file. If fputs() returns a value other than EOF, it means the write operation was successful, and we print a success message. Otherwise, we display an error message.
Finally, we close the file using fclose() to free up system resources.

Make sure to include proper error handling and check the return values of file operations for robust code.

Reading File : fgets() function

Certainly! Here’s an example of using the fgets() function to read a string from a file in C:

#include <stdio.h>

int main() {
    FILE *file = fopen("file.txt", "r");
    if (file != NULL) {
        char buffer[100];
        if (fgets(buffer, sizeof(buffer), file) != NULL) {
            printf("String read from the file: %s\n", buffer);
        } else {
            printf("Error reading from the file.\n");
        }
        fclose(file);
    } else {
        printf("Error opening the file.\n");
    }

    return 0;
}

In this example:

We include the <stdio.h> header file, which contains the necessary definitions for file operations.
We open the file “file.txt” in read mode using fopen(). If the file is opened successfully, a FILE pointer (file) is returned. Otherwise, we display an error message.
We define a character array buffer with a size of 100. This array will store the string read from the file.
We call fgets() to read a string from the file into the buffer. The sizeof(buffer) argument specifies the maximum number of characters to read from the file.
If fgets() returns a non-NULL value, it means the read operation was successful. We print the string read from the file using printf(). Otherwise, we display an error message.
Finally, we close the file using fclose() to free up system resources.

Make sure to include proper error handling and check the return values of file operations for robust code.